The olive flounder ( Paralichthys olivaceus), bastard halibut, Japanese flounder or Korean halibut is a temperate marine species of Paralichthyidae native to the North-western Pacific Ocean. It is the highest valued finfish in the world, known to be excellent for aquaculture due to a rapid growth rate and popularity in Japan and Korea.
Names
In Japanese, olive flounder is called
hirame (ヒラメ). In Korean, it is called
gwangeo (). In Chinese, it is called
yaping (牙鮃) or
biankouyu (扁口魚).
In English, it is often referred to as "Japanese flounder" or "Korean flatfish" when mentioned in the context of those countries.
Description
It reaches a length of and a weight of .
In 2017 its genome and transcriptome was sequenced as a model to study flatfish asymmetry.
File:Paralichthys olivaceus Umigatari.jpg|Specimen at Joetsu Aquarium
File:Hirame.jpg|Closeup of eyes
Habitat and diet
The olive flounder is often found in soft and muddy offshore, coastal areas where the water level goes down to 100 m in depth. The temperature of water in these areas range from 21–24 °C or 69–75 °F.
[ Some flounder have been found in the Mariana Trench.
]
Olive flounder typically eat fish spawn, crustaceans, polychaetes, and small fish.
Life cycle
Olive flounder spawn anytime from January through August in shallow water, roughly about 70 cm in depth. The egg and larvae remain that way for about 24–50 days after hatching. Once they begin their metamorphosis process, they move towards more sandy areas and feed on shrimp. After achieving metamorphosis, the flounder move offshore and begin feeding on bigger fish in order to grow to their adult size.[
]
How they become "flatfish"
Olive flounder first start out upright like normal fish, but then after 24 to 50 days after hatching they turn onto their side. Their previous side now becomes their belly or their underside and then their eye and nostril move towards what is now considered the back. This process is typically called the "metamorphosis."[
]
Aquaculture
The olive flounder is the most common flatfish species raised in aquaculture in Korea. They are raised in Japan and China as well. It is the most highly prized of the Japanese flounders. Although the aquaculture for the olive flounder started from the late 1980s, its commercial production didn't begin on a major scale until the 1990s in Korea.
Parasites and food poisoning
The Kudoa septemlineata has been described in 2010 from olive flounder from Korea.[ ] and suckling mice[ ] showed that K. septemlineata spores were excreted in faeces and did not affect the gastrointestinal tract.
As food
Oliver flounder is widely eaten as food in East Asia, often raw.
File:Korean cuisine-Hoe-01.jpg|Korean hoe
File:Sushiro---2020-02-29 001.jpg|Japanese sushi
File:Olive flounder carpaccio.jpg|Italian carpaccio
File:Hirame flatfish front.JPG
File:Hirame flatfish 5mai 2.JPG
Appearances in media
The olive flounder has appeared in the video game series Animal Crossing as one of the various fish species the player is able to catch using a fishing rod.
